The C-H stretching fundamental of the free radical HCCN has been investigated under high resolution using infrared kinetic spectroscopy. This transient molecule was produced by the flash photolysis of dibromoacetonitrile (Br\sb2HCCN) at 193 nm and its transient infrared absorption spectrum probed using a color center laser. Spectra of the molecule were collected between 3182 and 3274 cm\sp−1. The rotational analysis of the ν\sb1 fundamental places its origin at 3246.657 cm\sp−1. Four hot bands associated with the bending vibrations have been observed; the vibrational and rotational assignment of three of these bands ν\sb1+ν\sb5−ν\sb5, ν\sb1+ν\sb4−ν\sb4, and ν\sb1+2ν\sb5\sp±2−2ν\sb5\sp±2 is definite. The ν\sb5 energy was obtained by measuring the intensity of a line of the ν\sb1+ν\sb5−ν\sb5 band relative to one of the fundamental and calculating the energy assuming a room temperature Boltzmann distribution. A comparison of this energy with that of quasilinear fulminic acid, HCNO, and with theoretical calculations suggests a similar floppy HCX bending potential.